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Not only that, but the blockchain is not even immutable... Forks happen all the time and the developers end up arbitrarily choosing which fork is the real block

by hudon 9y ago

Not only that, but the blockchain is not even immutable... Forks happen all the time and the developers end up arbitrarily choosing which fork is the real blockchain. Anyone that was using the other fork in the meantime sees their chain mutate (gets wiped out, essentially) or be given a different name. So basically even IF the blockchain was not costly, the nation would need to control the developers to control the blockchain in the case of consensus failure (fork) to make sure no one messes with the election results.

darawk 9y ago
> Not only that, but the blockchain is not even immutable... Forks happen all the time and the developers end up arbitrarily choosing which fork is the real blockchain. Anyone that was using the other fork in the meantime sees their chain mutate (gets wiped out, essentially) or be given a different name. Yes they are. That's not what 'immutable' means. Immutability refers to an inability to change the past. Not an inability to fork the future. A blockchain is a persistent, immutable data structure. This is just a simple fact of computer science.
- hudon 9y ago
  When a chain fails to find consensus and forks due to different consensus rules, the 2 chains persist until the developers tell us which chain is the right one. Let's take the 2013 Bitcoin fork for example. OK now a merchant who has accepted Bitcoin on one chain could have had a transaction that was 20 blocks deep. Then, when the miners decide to abandon that chain and obey the developers and go on the other chain, the merchant's transaction is no longer confirmed if it wasn't played on the other chain. This is how blockchain consensus failures change the past of the ledger and therefore how the blockchain fails to be immutable by your definition. side note: I'd be wary of calling blockchain's consensus mechanism "computer science", it's more of a social consensus when consensus rules are different (ie. when forks are involved).
  - darawk 9y ago
    I didn't say consensus can't fail. I said it's immutable: https://en.wikipedia.org/wiki/Immutable_object https://en.wikipedia.org/wiki/Immutable_object Blockchains are immutable. Immutability is the property you want for elections. Blockchains are absolutely computer science. The consensus PoW mechanism is not part of 'blockchains'. It is a part of cryptocurrencies. Blockchains are simply a log-structured Merkle tree.
    - hudon 9y ago
      Repeating things don't make them true. You defined immutability as the inability of changing the past. I have provided you an example of the past of Bitcoin being changed (24 blocks were invalidated). I await your rebuttal.
      - darawk 9y ago
        That isn't changing the past. It's changing the interpretation of the past. The old transactions are still there, they're just not considered valid. That's fine. An election blockchain can't enforce its result anyway. A dictator can always simply say "yep, I got voted against, but too bad, i'm staying". What's important though, is that in a blockchain based system, that dictator would not be able to claim legitimacy convincingly. We would know and be able to prove that they invalidated or ignored the results. They cannot invalidate/ignore the true tally without everyone knowing they did it, just like you know that those Bitcoin transactions were invalidated. That is exactly the point.
        hudon 9y ago
        If I had a data structure whose contents could be interpreted differently by different parties, I'd have a very hard time convincing stakeholders that it was immutable... and I'd feel bad trying to do so. > We would know and be able to prove that they invalidated or ignored the results To your new point, though, picture this: it's 2016 and you're running your election on the blockchain. Unfortunately, a consensus bug in the blockchain causes the updated nodes (say, half the network that updated) to split. The devs decide to go forward with the new consensus rules and abandon the other chain. However, we find that the tally on the abandoned chain elected Hilary and the tally on the new chain elects Trump. What happened? Were the devs co-erced? Did they introduce the bug themselves? Why was the tally different on the abandoned chain? Who collected the tally and wrote it to the blockchain? How do we know or prove the legitimacy of the chosen blockchain over the abandoned one, as you claim?

by hudon 9y ago

darawk 9y ago

> Not only that, but the blockchain is not even immutable... Forks happen all the time and the developers end up arbitrarily choosing which fork is the real blockchain. Anyone that was using the other fork in the meantime sees their chain mutate (gets wiped out, essentially) or be given a different name. Yes they are. That's not what 'immutable' means. Immutability refers to an inability to change the past. Not an inability to fork the future. A blockchain is a persistent, immutable data structure. This is just a simple fact of computer science.

hudon 9y ago
When a chain fails to find consensus and forks due to different consensus rules, the 2 chains persist until the developers tell us which chain is the right one. Let's take the 2013 Bitcoin fork for example. OK now a merchant who has accepted Bitcoin on one chain could have had a transaction that was 20 blocks deep. Then, when the miners decide to abandon that chain and obey the developers and go on the other chain, the merchant's transaction is no longer confirmed if it wasn't played on the other chain. This is how blockchain consensus failures change the past of the ledger and therefore how the blockchain fails to be immutable by your definition. side note: I'd be wary of calling blockchain's consensus mechanism "computer science", it's more of a social consensus when consensus rules are different (ie. when forks are involved).
- darawk 9y ago
  I didn't say consensus can't fail. I said it's immutable: https://en.wikipedia.org/wiki/Immutable_object https://en.wikipedia.org/wiki/Immutable_object Blockchains are immutable. Immutability is the property you want for elections. Blockchains are absolutely computer science. The consensus PoW mechanism is not part of 'blockchains'. It is a part of cryptocurrencies. Blockchains are simply a log-structured Merkle tree.
  - hudon 9y ago
    Repeating things don't make them true. You defined immutability as the inability of changing the past. I have provided you an example of the past of Bitcoin being changed (24 blocks were invalidated). I await your rebuttal.
    - darawk 9y ago
      That isn't changing the past. It's changing the interpretation of the past. The old transactions are still there, they're just not considered valid. That's fine. An election blockchain can't enforce its result anyway. A dictator can always simply say "yep, I got voted against, but too bad, i'm staying". What's important though, is that in a blockchain based system, that dictator would not be able to claim legitimacy convincingly. We would know and be able to prove that they invalidated or ignored the results. They cannot invalidate/ignore the true tally without everyone knowing they did it, just like you know that those Bitcoin transactions were invalidated. That is exactly the point.
      - hudon 9y ago
        If I had a data structure whose contents could be interpreted differently by different parties, I'd have a very hard time convincing stakeholders that it was immutable... and I'd feel bad trying to do so. > We would know and be able to prove that they invalidated or ignored the results To your new point, though, picture this: it's 2016 and you're running your election on the blockchain. Unfortunately, a consensus bug in the blockchain causes the updated nodes (say, half the network that updated) to split. The devs decide to go forward with the new consensus rules and abandon the other chain. However, we find that the tally on the abandoned chain elected Hilary and the tally on the new chain elects Trump. What happened? Were the devs co-erced? Did they introduce the bug themselves? Why was the tally different on the abandoned chain? Who collected the tally and wrote it to the blockchain? How do we know or prove the legitimacy of the chosen blockchain over the abandoned one, as you claim?